1. Field of the Invention
The present invention relates to an optical cross-coupling apparatus for performing parallel optical connection in highly parallel optical information transmission or optical information processing that utilizes optical fibers.
2. Description of the Prior Art
Conventionally, in highly parallel optical information transmission or optical information processing that utilizes optical fibers, connectors for connecting a large number of optical fibers at once are required. For example, FIGS. 1A and 1B are plan and front views, respectively, of an example of such connectors that are formed as one-dimensional fiber array connectors. In each of these one-dimensional fiber array connectors, multi-type tape-like optical fibers 41 are aligned one-dimensionally with a multi-type ferrule 42 made of a resin or the like. A guide pin 43 is provided to project from one portion of one side of each connector, and a guide pin hole 44 is formed in the other portion of one side of each connector. When the guide pins of the two connectors are fitted in the guide pin holes of the opposing connectors, the end faces of the multi-type tape-like optical fibers of one connector are brought into contact with those of the opposite connector, thereby allowing transmission of light signals between the two connectors.
In these conventional one-dimensional fiber array connectors, merely the opposing one-dimensional optical fibers of the two connectors are connected to each other, and the plurality of one-dimensional fiber arrays cannot be connected crosswise. For example, apparatuses as shown in FIG. 2 are available. In one apparatus, one end portion of an optical fiber bundle 102 is connected to a transmission board 101 through a selection circuit 103 and a surface light-emitting element array 104, and a one-dimensional fiber array connector 105 is connected to the other end portion of the optical fiber bundle 102. In the other apparatus, one end portion of an optical fiber bundle 202 is connected to a reception board 201 through a light-receiving element array 203 and an amplifier 204, and the other end portion of the optical fiber bundle 202 is connected to a one-dimensional fiber array connector 205. A plurality of such apparatuses are provided to each of the transmission and reception sides, thus constituting a space-division optical switch that requires crosswise transmission of optical signals between the respective transmission boards 101 and the respective reception boards 201.
In this case, the plurality of one-dimensional fiber array connectors 105 on the transmission side are connected to one surface of a cross-coupling portion 301, and similarly the plurality of one-dimensional fiber array connectors 205 are connected to the other surface of the cross-coupling portion 301. A large number of optical fibers are arranged crosswise and formed in the cross-coupling portion 301 in order to set the optical fibers 102 and 202 connected to the two surfaces of the cross-coupling portion 301 in a crossing state. Thus, the large number of optical fibers of the respective connectors 105 and 205 are cross-connected to each other through these internal crossing optical fibers.
In this manner, conventionally, when connecting a plurality of one-dimensional fiber array connectors with another plurality of one-dimensional fiber array connectors crosswise, a cross-coupling portion in which a large number of optical fibers are arranged crosswise and which has a complicated arrangement is required. However, such a cross-coupling portion is very difficult to manufacture and is difficult to manufacture on a mass-production basis. A different exclusive cross-coupling portion must be manufactured for a one-dimensional fiber array connector having a different standard, leading to different design and manufacture. As a result, a cross-coupling portion cannot be supplied at a low cost.